Method and Apparatus for Making Absorbent Structures with Absorbent Material

ABSTRACT

A method and apparatus for making specific absorbent structures with an absorbent layer with absorbent material with therein substantially longitudinally extending strips that are free of absorbent material, using or having thereto a moving endless surface with receptacle(s) with specific longitudinally extending rods; and specific absorbent structures obtained therewith, suitable for absorbent articles, such as diapers and sanitary napkins.

FIELD OF THE INVENTION

The present disclosure relates to a method for making specific absorbentstructures with absorbent material, optionally with longitudinallyextending strips that are free of absorbent material, and apparatus formaking such absorbent structures, and specific absorbent structuresobtained therewith, suitable for absorbent articles, such as diapers andsanitary napkins.

BACKGROUND OF THE INVENTION

Absorbent articles, such as diapers and sanitary napkins, absorb andcontain body exudates. They also are intended to prevent body exudatesfrom soiling, wetting, or otherwise contaminating clothing or otherarticles, such as bedding, that come in contact with the wearer. Adisposable absorbent article, such as a disposable diaper, may be wornfor several hours in a dry state or in a urine-loaded state.Accordingly, efforts have been made toward improving the fit and comfortof the absorbent article to the wearer, both when the article is dry andwhen the article is fully or partially loaded with liquid exudate, whilemaintaining or enhancing the absorbing and containing functions of thearticle.

Efforts have also been made to make absorbent article thinner when dry,to improve the comfort of such articles.

Some absorbent articles, like diapers, contain absorbent material suchas super absorbent polymers that absorbs very high quantities of liquidand causes the absorbent article to swell significantly. Such articleswill thus increase significantly in volume during use, and sometimes inparticular in the crotch area between the wearer's legs, which mayrender the article uncomfortable.

There may thus still be a need to further improve the performance/fit ofsuch articles and/or the liquid transportation away from the crotch.There may also still be a need to further reduce the chance of leakageand to improve the efficiency of absorbency of an absorbent article,such as a diaper.

It has been found that improved liquid transportation can be achieved bythe provision of transportation channels for distributing liquid in theabsorbent article, e.g., the absorbent structure thereof. Furthermore,it has been found that improved fit can be obtained by providingabsorbent articles with absorbent structures wherein the absorbentmaterial is structured in longitudinal direction, optionally with areasthat comprise less or no absorbent material, for improved bendingflexibility in use (in the direction corresponding to the longitudinaldirection (e.g., this may be the machine direction). The presentdisclosure provides an apparatus and method for providing such absorbentstructures, and specific absorbent structures obtained thereby.

SUMMARY OF THE INVENTION

The present disclosure provides a method of making an absorbentstructure having an absorbent layer and therein longitudinally extendingstrips that are substantially free of absorbent material (100), saidabsorbent layer being supported on a supporting sheet (200), said methodcomprising the steps of:

-   -   i) providing a feeder (20; 60) with absorbent material (100);    -   ii) providing a moving endless surface (30), such as for example        a drum, moving in a machine direction (MD) having an outer shell        with one or more forming receptacles (33), having an average        longitudinal dimension and length (which may be in MD) and        having an average transverse dimension and width (which may be        in CD), said length being more than said width, said        receptacle(s) comprising a multitude of substantially        longitudinally extending rods (36), spaced apart from one        another in transverse direction, each rod (36) having a maximum        transverse dimension which is at least 0.3 mm and each of said        rods (36) having a top portion and an opposing bottom portion,        said bottom portion optionally being adjacent an inner grid        (37), and the minimum distance in transverse dimension between        neighboring rods (36) being at least 1 mm, and said rods (36)        each having an average height dimension (perpendicular to the        transverse and longitudinal dimensions) of at least 1 mm, said        moving endless surface (30) being connected to one or more        vacuum systems (38) applying a vacuum suction to said        receptacles (33) or part thereof,    -   iii) providing a supporting sheet (200) transporter (210);    -   iv) transporting said supporting sheet (200) to said outer        shell, onto said top portions of said rods (36);    -   v) optionally pulling said supporting sheet (200) partially in        between neighboring rods (36) by said vacuum suction, to form        undulations (201) in said supporting sheet (200) between said        rods (36) and to form crests (202) on said upper portion of said        rods (36) (as for example shown in FIG. 4);    -   vi) depositing with said feeder said absorbent material (100)        onto said supporting sheet (200) present on said forming        receptacles (33);    -   vii) pulling said absorbent material (100) with said vacuum        suction onto the supporting sheet (200) that is present between        neighboring rods (36), to form absorbent strips, optionally into        said undulations (201);    -   viii) optionally removing absorbent material (100) remaining on        said crests (202) of said supporting sheet (200);    -   ix) removing said supporting sheet (200) and said absorbent        material (100) from said moving endless surface (30);

to obtain said absorbent structure.

The present disclosure also provides an apparatus (1) for making anabsorbent structure having an absorbent layer and therein substantiallylongitudinally extending strips that are substantially free of absorbentmaterial (100), said layer being supported on a supporting sheet (200),said apparatus (1) comprising:

-   -   a feeder for feeding an absorbent material (100) to a moving        endless surface (30),    -   a supporting sheet (200) transporter (210), for transporting a        supporting sheet (200) to said moving endless surface (30); and    -   said moving endless surface (30) moving in a machine        direction (MD) having an outer shell with one or more forming        receptacles (33), as mentioned above, having a multitude of        substantially longitudinally extending rods (36), each rod (36)        having a maximum transverse dimension of at least 0.3 mm, each        of said rods (36) having a top portion (surface) and an opposing        bottom portion (surface), said bottom portion being adjacent an        inner grid (37), and the minimum distance in transverse        dimension between neighboring rods (36) being at least 1 mm, and        said rods (36) having an average height dimension (perpendicular        to the transverse and longitudinal dimensions) of at least 1 mm;        and    -   said moving endless surface (30) comprising a vacuum system (38)        applying a vacuum suction to said receptacles (33) or part        thereof; or any of the dimensions as describe above; and    -   said feeder optionally being a further moving endless surface        (20) with reservoir(s) for receiving and retaining a said        absorbent material (100) and transferring said absorbent        material (100) to said moving endless surface (30), said further        moving endless surface (20) being connected to a vacuum system        (28) to apply vacuum suction to said reservoir(s).

In some embodiments, in step vii), said absorbent structure comprise anabsorbent layer with absorbent material (100) formed into substantiallylongitudinally extending strips of absorbent material (100) on saidsupporting sheet (200), optionally in said undulations (201), withtherein between strips with substantially no absorbent material (100),optionally on said crests (202).

In some embodiments, step viii) is performed; hereto the supportingsheet (200) placed on the receptacle, or the part thereof that is tooverlap with the receptacle, may be wider than the width of thereceptacle, so-called over-in-feeding of the supporting sheet (200) intransverse dimension, e.g. in the transverse direction, for example theCross-machine dimension (CD). The receptacle(s) may have a first averagewidth (e.g. in CD) dimension and said supporting sheet (200) on saidreceptacle (33) has a second average width dimension (e.g. in CD), andthe ratio of said first to said second average width dimension is atleast 1:1.1, or at least 1:1.2, or at least 1:1.3, typically up 1:3.

The method may comprise the step of providing a first adhesiveapplication unit (50), and applying an adhesive to said absorbent layerprior to removing it from said moving endless surface (30), orimmediately subsequent thereto, and/or the step of providing a secondadhesive application unit (51), and applying an adhesive to saidsupporting sheet (200), prior to deposition of said absorbent material(100) thereon; for example, this may be done selectively, either to theareas of the supporting sheet (200) that are to meet with the rods (36),or the areas of the supporting sheet (200) that are to be in betweenneighboring rods (36); for example said adhesive may be applied only insubstantially longitudinal stripes on the areas of said supporting sheet(200) that coincides with said crests (202).

The method may be to provide a laminate of two of said absorbentstructures, e.g. the method may be such that said steps i) to vii) andix), and optionally step vii) are repeated to form a second absorbentstructure, and wherein the method comprises the subsequent step ofcombining said first absorbent structure and said second absorbentstructure, such that said absorbent materials (100) of both structuresare sandwiched between said supporting sheet (200) of the firststructure and the supporting sheet (200) of the second structure.

Some or each of said rods (36) may for example have said maximumtransverse dimension which is at least 1 mm, or at least 2 mm, or forexample at least 3 mm or at least 4 mm, and typically up to 20 mm or upto 15 mm or up to 10 mm; the minimum distance transversely in betweenneighboring rods (36) may for example be at least 2 mm, or at least 3mm, or at least 5 mm, or at least 10 mm, and for example up to 30 mm, orup to 20 mm; said rods (36) each may have an average height dimension offor example at least at least 2 mm, or for example at least 3 mm. Theremay for example be at least 5 rods (36), or for example at least 7 rods(36).

The method may comprise the step of providing a pressure roll (70) witha raised pressure pattern (71), corresponding to the pattern of saidrods (36) and/or said crests (202) if present, and mating said pressureroll (70) pattern with said absorbent structure, on the supporting sheetthereof, and/or on a further material, after such a further material issuperposed on said absorbent layer, (e.g. the supporting sheet (200) isfolded over it, a further supporting sheet (300) is placed on it, or andacquisition layer is placed on it, or a further absorbent structure isplaced on it, such that the absorbent material (100) is sandwichedbetween the two supporting sheets (200; 300), wherein said pressurepattern (71) mates with said supporting sheet (200), or said furthermaterial, in the areas where, on the opposite surface, no absorbentmaterial (100) is present

Said feeder is adjacent and in close proximity to said moving endlesssurface (30), and they transfer of said absorbent material (100) takesplace in a so-called meeting point. The feeder may be a further movingendless surface (20) with reservoir(s), such as a so-called print roll,and said method may comprise the steps of receiving absorbent material(100) on said further moving endless surface (20), retaining saidabsorbent material (100) in said reservoir(s) and transferring saidabsorbent material (100) to said moving endless surface (30); optionallysaid further moving endless surface's reservoir being formed by amultitude of grooves or a multitude of rows of cavities (22), eachgroove or row extending substantially longitudinally, said grooves orrows may be spaced from one another with raised strips. The method maycomprise the step that said raised strips and said rods (36) are matingduring the transfer of said absorbent material (100), e.g. in saidmeeting point.

Said receptacle (33) may have a front edge zone, and back edge zone,each extending the width/transverse dimension of said receptacle, andsaid front edge zone and/or back edge zone do not comprise said rods(36), with therein between a central zone with rods (36); or whereinsaid receptacle (33) has a centre region, front region and back region,and said receptacle (33) comprises said rods (36) in said front regiononly, or in said centre region only, or in said front and centre regiononly. Said receptacle (33) may have in said region(s) or zone(s) thatnot comprising said rods (36) a higher friction than said rods (36).

For example, as also shown in FIG. 6 for example, said central zone (B)having said rods, having a lower friction than said front edge zone andback edge zones (A; C) without rods. This can aid to ensure thesupporting sheet (200) is pulled in between the rods (36) in the lowfriction zone, and less or not at all in the high friction zone.

The apparatus (1) may comprises additional units, such as a unit (300)to cover the absorbent structure's absorbent layer with a furthermaterial, as described herein; and/or an adhesive application unit (51)upstream from said moving endless surface (30), and/or an adhesiveapplication unit (50), positioned downstream of the point where thefeeder and said moving endless surface (30) meet (meeting point); and/ora pressure roll (70) with a raised pressure pattern (71), as describedherein.

The present disclosure also relates to absorbent structures obtainablewith the method or apparatus (1) herein, in particular those where theabsorbent layer comprises such strips that comprise no absorbentmaterial (100), and/or wherein said supporting sheet (200) comprisessaid undulations (201) with absorbent material (100) and crests, notcomprising absorbent material (100), and/or wherein an adhesive isapplied to immobilize said absorbent material (100), and/or wherein saidabsorbent structure comprises a further material on said absorbentlayer, e.g. another absorbent structure, further supporting sheet (300)or acquisition layer, and a pressure is applied, to pressurize saidsupporting sheet (200) (further) into said strips where no absorbentmaterial (100) is present, to render said strips more permanent in use.

The absorbent material (100), e.g. including or being a particulatesuperabsorbent polymer material, may be deposited on the supportingsheet (200) such that the absorbent layer comprises or consists ofabsorbent material (100) strips, extending substantially in thelongitudinal direction, with therein between strips with no absorbentmaterial (100), e.g. in the form of an absorbent layer with absorbentmaterial (100) with therein substantially longitudinally extendingstrips that are free of absorbent material (100); such strips withoutabsorbent material (100) may for example only extend at the most 90% orat the most 80%, or for example at the most 70% or for example at themost 60% of the full length of the absorbent layer. Said strips withoutabsorbent are material may optionally have an average width dimension ofat least 2 mm, or at least 3 mm; said strips may have any of thedimensions and shapes and positions described herein for said rods (36)and/or raised portions.

It should be understood that above and following description appliesequally to the method and the apparatus (1) of the present disclosure,and the absorbent structure obtained therewith, unless stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an apparatus of the present disclosure.

FIG. 2 is a perspective view of an apparatus of the present disclosure.

FIG. 3 is a perspective view of optional further units of the apparatusof the present disclosure, combining absorbent structures into anabsorbent article and bonding it.

FIG. 4 is a partial and cross-sectional view of a moving endless surfaceand a receptacle thereof, of an apparatus of the present disclosure.

FIG. 5 is a top view of a receptacle during production of an absorbentstructure herein.

DETAILED DESCRIPTION OF THE INVENTION

As summarized above, this invention encompasses a method and apparatus(1) for making an absorbent structure useful for absorbent articlecomprising absorbent material (100), optionally at least, or only,particulate superabsorbent polymer material, and preferred absorbentlayers. Embodiments of such method and apparatus (1) and resultingabsorbent structures and absorbent articles are further described hereinbelow, after the following definitions.

DEFINITIONS

“Absorbent structure” refers to a three-dimension structure with alongitudinally dimension and perpendicular thereto a transversedimension and perpendicular to both a height dimension, and thatcomprises at least an absorbent material (100) and a supporting sheet(200), and that is useful in an absorbent article.

“Absorbent layer” refers to a three dimensional layer of absorbentmaterial (100), formed by deposition of absorbent material (100) (s)onto the supporting sheet (200), and it may comprise other components,e.g. deposited onto the supporting sheet (200).

“Absorbent material (100)” refers to a material or mixture of materialsthat can absorb and retain bodily fluids; it typically includes orconsists of Superabsorbent polymer material”. “Superabsorbent polymermaterial” (also known as “absorbent gelling material,” or “AGM,”“superabsorbent,”) refer to polymeric materials that can absorb at least10 times their weight of an aqueous 0.9% saline solution as measuredusing the Centrifuge Retention Capacity test (Edam 441.2-02)., i.e.having a CRC of at least 10 g/g. This is typically in particulate form.

“Particulate” is used herein to refer to a material which is inparticulate form so as to be flowable in the dry state.

“Absorbent article” refers to a device that absorbs and contains bodyexudates, and, more specifically, refers to devices that are placedagainst or in proximity to the body of the wearer to absorb and containthe various exudates discharged from the body. Absorbent articles mayinclude adult and infant diapers, including pants, such as infanttraining pants and adult incontinence undergarments, and femininehygiene products, such as sanitary napkins and panty-liners and adult incontinent pads, and breast pads, care mats, bibs, wound dressingproducts, and the like. Absorbent articles may further include floorcleaning articles, food industry articles, and the like. As used herein,the term “body fluids” or “body exudates” includes, but is not limitedto, urine, blood, vaginal discharges, breast milk, sweat and fecalmatter.

“Diaper” refers to an absorbent article generally worn by infants andincontinent persons about the lower torso so as to encircle the waistand legs of the wearer and that is specifically adapted to receive andcontain urinary and fecal waste.

“Pant” or “training pant”, as used herein, refer to diaper having awaist opening and leg openings designed for infant or adult wearers. Apant may be placed in position on the wearer by inserting the wearer'slegs into the leg openings and sliding the pant into position about awearer's lower torso. A pant may be preformed by any suitable techniqueincluding, but not limited to, joining together portions of the articleusing refastenable and/or non-refastenable bonds (e.g., seam, weld,adhesive, cohesive bond, fastener, etc.). A pant may be preformedanywhere along the circumference of the article (e.g., side fastened,front waist fastened). While the terms “pant” or “pants” are usedherein, pants are also commonly referred to as “closed diapers,”“prefastened diapers,” “pull-on diapers,” “training pants,” and“diaper-pants”. Suitable pants are disclosed in U.S. Pat. No. 5,246,433,issued to Hasse, et al. on Sep. 21, 1993; U.S. Pat. No. 5,569,234,issued to Buell et al. on Oct. 29, 1996; U.S. Pat. No. 6,120,487, issuedto Ashton on Sep. 19, 2000; U.S. Pat. No. 6,120,489, issued to Johnsonet al. on Sep. 19, 2000; U.S. Pat. No. 4,940,464, issued to Van Gompelet al. on Jul. 10, 1990; U.S. Pat. No. 5,092,861, issued to Nomura etal. on Mar. 3, 1992; U.S. Patent Publication No. 2003/0233082 A1,entitled “Highly Flexible And Low Deformation Fastening Device”, filedon Jun. 13, 2002; U.S. Pat. No. 5,897,545, issued to Kline et al. onApr. 27, 1999; U.S. Pat. No. 5,957,908, issued to Kline et al on Sep.28, 1999.

A “nonwoven” is a manufactured sheet, web or batt of directionally orrandomly orientated fibers, bonded by friction, and/or cohesion and/oradhesion, excluding paper and products which are woven, knitted, tufted,stitch-bonded incorporating binding yarns or filaments, or felted bywet-milling, whether or not additionally needled. The fibers may be ofnatural or man-made origin and may be staple or continuous filaments orbe formed in situ. Commercially available fibers have diameters rangingfrom less than about 0.001 mm to more than about 0.2 mm and they come inseveral different forms: short fibers (known as staple, or chopped),continuous single fibers (filaments or monofilaments), untwisted bundlesof continuous filaments (tow), and twisted bundles of continuousfilaments (yarn). Nonwoven fabrics can be formed by many processes suchas meltblowing, spunbonding, solvent spinning, electrospinning, andcarding. The basis weight of nonwoven fabrics is usually expressed ingrams per square meter (gsm).

“Substantially cellulose free” is used herein to an absorbent layerstructure (or core), that contains less than 5% by weight cellulosicfibers.

“Thickness” and “height” are used herein interchangeably.

A absorbent structure and absorbent layer thereof, and a receptacle (33)herein each have a longitudinal dimension and average length, and thismay be corresponding the machine direction (MD), and perpendicularthereto a transverse dimension, and average width, which may becorresponding to the cross-machine direction (CD), said width being lessthan said length; and a front region, back region and central region,each being ⅓ of the average length of the structure/layer, respectively,and having each the full width. Each has longitudinal edges and edgezones, extending the full length thereof—as further described below.

Moving Endless Surface (30)

The method and apparatus (1) herein deploy a moving endless surface(30), moving in a machine direction (MD). It has an outer shell with oneor more forming receptacles (33), for receiving thereon or therein thesupporting sheet (200) (which may be a web material, as described hereinbelow, or individual sheets that are placed on a receptacle). Thefollowing is described for a single receptacle (33) but may apply toeach receptacles (33) of the moving endless surface (30)'s outer shell.An exemplary apparatus is shown in FIG. 1.

Each receptacle (33) corresponds typically to an absorbent structure tobe produced, as suitable for an absorbent article. The supporting sheet(200) may be a web material, so the method and apparatus (1) herein canthus serve to produce a web of such absorbent structures that are thensubsequently separated into individual structures.

The moving endless surface (30) may have or be a rotating surface, suchas a rotating, e.g. cylindrical, drum. It may be that the outer shellmoves, e.g. rotates, around a stationary inner chamber, e.g. a so-calledstator (230).

The outer shell and the receptacle (33) have a transverse direction andaverage transverse dimension (average width), and the receptacle (33)has longitudinal direction and average longitudinal dimension (averagelength), perpendicular thereto.

The receptacle (33) has peripheral edges, and peripheral edge zones,including opposing longitudinal edges and edge zones, and a transversefront edge and front edge zone A, and a transverse back edge and backedge zone C, with a central zone B in between. Each of said front andback edge zones, extending the complete transverse dimension, may forexample be in longitudinal dimension from about 5% to about 20%, or to15%, or to 10% of the average longitudinal dimension of the receptacle.

Each of said longitudinal edge zone may extend the length and may havean average transverse dimension of for example from about 5% to about20%, or typically to about 15% or to about 10% of the average transversedimension of the receptacle.

The receptacle (33) may in addition, or alternatively, comprise a frontregion, back region and central region, therein between, as furtherdescribed below. The central region may be for example the central ⅓ ofthe receptacle, extending the full transverse dimension.

The receptacle (33) comprises a multitude of substantiallylongitudinally extending rods (36), spaced apart from one another intransverse direction. The rods (36) are such that they form or partiallyform the most outer surface of said receptacle, so that the supportingsheet (200) is received and carried by said rods (36). Thus, betweenrods (36) there is a spacing where the supporting sheet (200) may not besupported directly by the receptacle, or may not be in direct contactwith the receptacle. For example, FIG. 2 shows such a receptacle, andFIG. 4 shows a cross-section thereof.

The receptacle (33) may comprise said rods (36) over substantially thewhole length of the receptacle; or for example over the whole lengthexcept the front edge zone and/or back edge zone; or, in someembodiments herein, the rods (36) may be present only in said centralregion; in some embodiments, the rods (36) may be present in the frontregion and optionally the central region, but not the back region; insome embodiments, the rods (36) may be present in the back region andoptionally the central region, but not the front region.

The receptacle (33) may comprise such rods (36) over the whole width ofsaid receptacle; or for example over the whole width except in saidlongitudinal edge zones.

In any of these embodiments, the zone(s) or region(s) not comprisingsaid rods (36) is herein referred to as rod-free zone or rod-freeregion; in said rod-free region or rod-free zone the supporting sheet(200) may be deposited onto said inner grid (37) (e.g. a mesh material)directly, or there may be an outer grid present, typically in the sameplane as the rods (36); for example an outer grid made of a combinationof transverse and longitudinal rods (36) that are intersecting in thesame plane, like a mesh), or a plate with optionally apertures forvacuum suction. This is for example shown in FIG. 4.

Said receptacle (33) may have in said region(s) or zone(s) that notcomprising said rods (36) a higher friction than aid rods (36). This canaid to ensure the supporting sheet (200) is pulled in between the rods(36) in the low friction zone, and less or not at all in the highfriction zone. For example, the receptacle (33) can be made of a higherfriction material (e.g. a material with a less even surface), or may betreated with an friction-increasing agents, in those zones or regionsnot comprising said rods (36); or for example said zones or regions withrods (36), or only said rods (36), can be made of a lower frictionmaterial, or treated with friction-reducing agent.

A rod (36) is considered substantial longitudinally extending, if itslongitudinal (length) extension is more than its transverse (width)extension. Thus, a rod (36) may be under an angle with the longitudinalaxis of the receptacle, provided said angle is less at the most 30°; ora rod (36) may be slightly curved (as described below); or a rod (36)may be wavy; or a rod (36) may comprise an angle, provided said angle isat least 120°, as described below; provided, in each case, itslongitudinal (length) extension is more than its transverse (width)extension, e.g. they extend at least 50% or at least 100% more inlongitudinal dimension of said receptacle (33) than in transversedimension.

The rod (36) may be any shape or form. It may have a square,rectangular, round, oval or hexagonal cross-section in transversedimension, for example. Each rod (36) has a top portion (which may bethe top surface for, for example, rods (36) that have a square orrectangular cross-section) and an opposing bottom portion or surface.Said top portion or surface is then in contact with the supporting sheet(200); said bottom surface may be adjacent (e.g.: on) an, at leastpartially, air-permeable inner grid (37).

In some embodiments, it may be preferred that the rod (36) is generallyrectangular with optionally a triangular-shaped top portion.

Neighboring rods (36) are spaced apart, e.g. with a minimum distance(transversely) of for example at least 2 mm, or at least 3 mm, or atleast 5 mm, or for example at least 10 mm.

Two or more rods (36) may be parallel to one another, so that thespacing distance between parallel neighboring rods (36), transversely,is at least said 2 mm along substantially the whole length.

Thus, there is a void volume neighboring rods (36), e.g. between theinner grid (37) if present, and neighboring rods (36), and said voidvolume extends substantially in longitudinal direction in between saidneighboring rods (36).

This void volume can serve to receive the supporting sheet (200)therein, as an undulation, and optionally said absorbent material (100).

Each rod (36) has a maximum transverse dimension which may be at least0.3 mm, optionally at least 0.5 mm, or at least 1.0 mm, or at least 2mm, and in some embodiments, for example at least 3 mm or at least 4 mm,and for example up to 20 mm, or up to 15 mm or for example up to 10 mm.

Each rod (36) has a maximum and average height dimension. Each rod (36)may for example have an average or maximum height dimension of at least2 mm, or at least 3 mm, or at least 4 mm, or at least 5 mm.

This may be optionally substantially equal to the distance from the topof a rod (36) to the inner grid (37), if present.

The receptacle (33) may for example have at least 2 such rods (36), orfor example at least 4 such rods (36), or for example at least 5 or atleast 7 such rods (36).

The rods (36) may be slightly curved (for example having a singlecurvature), having a curvature with a radius that is at least equal to,optionally at least 1.5 times or at least 2 times, the averagetransverse dimension of the receptacle; and/or having a curvaturefollowing for example the contour of the closest longitudinal side edge;and/or having multiple small curvatures, said rod(s) being then forexample longitudinally extending wavy rod(s). In any such case, saidrods (36) are considered to extend substantially longitudinally, as saidout above.

In some embodiments the rods (36) are straight and parallel to thelongitudinal axis of the receptacle.

In some embodiments it may be preferred that the rods (36) are concave,wherein the longitudinal centre of the rod (36) is closer to thelongitudinal axis of the receptacle (33) than the end point(s), andwherein the radius of curvature is at least 1.5 times the transversedimension of the receptacle, optionally at least 2 times.

The moving endless surface (30) is connected to a vacuum system (38)that can apply a vacuum on said outer shell/receptacles (33), to pullthe supporting sheet (200) onto said outer shell/receptacles (33), andto retain the absorbent material (100) thereon. The moving endlesssurface (30) may thus move adjacent a vacuum system, such as a vacuumchamber (s) (38), that is present adjacent the outer shell (on theopposite side to the rods (36)). The vacuum chamber(s) may be present ina stator (230) around which the moving endless surface (30) rotates.

The outer shell is hence at least partially air-permeable, which meansit is such that it in air communication with said vacuum system, e.g.provided affective vacuum pressure can be applied through said shellonto said supporting sheet (200). For example, the rods (36) themselvesmay for example not be air-permeable, i.e. not being in direct aircommunication with said vacuum system. The surface area between rods(36) should however generally be air-permeable. Hence, the inner grid(37) may be air-permeable, e.g. it may be a mesh material, for example.

In some preferred embodiments, the supporting sheet (200) is depositedonto said rods (36) and it bends in between neighboring rods (36), e.g.due to the vacuum suction to form thereby in said sheet undulations(201) between neighboring rods (36), and crests (202) supported on saidrods (36) (on said top surface or top portion). The inner grid (37) maycontrol/determine the size (height) of said undulations (201). This isfor example shown in FIGS. 4 and 5.

The supporting sheet (200) is transferred from a transfer means, such atransfer roll, to said moving endless surface (30) and deposited ontosaid outer surface/receptacles (33), e.g. onto said rods (36) at least.It may be transported to the outershell and receptacles (33) thereof asa web, or as individual sheets.

The supporting sheet (200) may be a nonwoven material, as furtherdescribed herein. Subsequently, said absorbent material (100) may bedeposited onto said supporting sheet (200), on said receptacles (33).The absorbent material (100) may be deposited such that it is onlypresent on the portions (e.g. strips) of the supporting sheet (200) thatis present between neighboring rods (36), e.g. in said undulations(201). Thereto, specific feeders as described below may be used.Alternatively, or in addition, the vacuum may be such that it pulls theabsorbent material (100) to or towards the portions of the supportingsheet (200) present between neighboring rods (36), e.g. into saidundulations (201). Substantially no absorbent material (100) may forexample be present on the supporting sheet (200) present on said rods(36), e.g. on said crests, as for example shown in FIGS. 4 and 5.

Alternatively, or in addition, absorbent material (100) deposited ontothe portions of the supporting sheet (200) on said rods (36) (e.g. saidcrests (201)) may be removed by means known in the art, such as ascraper or doctor blade.

Alternatively, or in addition, the supporting sheet (200) may compriseadhesive. For example said adhesive may be present on said portions ofsaid supporting sheet (200) that are between neighboring rods (36), e.g.said undulations (201). This may help to adhere the absorbent material(100) in such portions, e.g. on said undulations (201). The supportingsheet (200) may then, prior to addition of the absorbent material (100),comprise no adhesive applied on said portions supported by said rods(36), e.g. said crests (202), so that less or no absorbent material(100) adheres in said portions, e.g. crests. This is for example shownin FIG. 1.

By use of these rods (36), the absorbent structure may have saidabsorbent material (100) deposited in the form of strips of absorbentmaterial (100) (e.g. corresponding to said undulations (201)), withtherein in between strips that are free of such absorbent material (100)(e.g. corresponding to aid crests (202)); and/or said absorbent layerformed herein may be a layer of absorbent material (100) with stripsthat are substantially free of absorbent material (100) (e.g. the crests(202) of said supporting sheet (200)).

As described above, the supporting sheet (200) may be transferred tosaid moving endless surface (30) such that it forms undulations (201)and crests (202). Then, when the supporting sheet (200) is removed fromsaid moving endless surface (30), the supporting sheet (200) is pulledsubstantially flat, resulting in an absorbent structure withsubstantially longitudinally extending strips (that correspond to thecrests (202) of said material) that comprise substantially no absorbentmaterial (100). This is for example shown in FIG. 5.

In some embodiments, the moving endless surface (30) may for examplehave a speed of at least 1000 part per minute and/or a speed of at least4.5 m/s, or at least 6 m/s, or at least 8 m/s.

Feeder (20; 60)/Further Moving Endless Surface (20)

The absorbent material (100) may be delivered to the supporting sheet(200) by a feeder (60; 20) placed adjacent and in close proximity tosaid moving endless surface (30), for example substantially above saidsurface.

The absorbent material (100) may be deposited onto said supporting sheet(200) by any method, including substantially continuously.

The feeder herein is capable of holding the absorbent material (100),and letting it flow to the supporting sheet (200) on said moving endlesssurface (30). The point or area where the material leaves the feeder isherein referred to as meeting point.

The feeder may be a (e.g. stationary) hopper (60) with a containerportion, to hold the material, e.g. having a volume of at least 1000cm³, and a guiding portion, e.g. a pipe-shapes portion, having one ormore walls that guides the material from the container portion to thesupporting sheet (200) on the moving endless surface (30).

In a preferred embodiment, the absorbent material (100) is deposited onthe supporting sheet (200) carried on said moving endless surface (30)by a further moving endless surface (20) that moves, moving in a machinedirection, e.g. rotates, adjacent and in close proximity to said movingendless surface (30). In such a case, a hopper (60), as for exampledescribed above, may feed the absorbent material (100) to this furthermoving endless surface (20).

The further moving endless surface (20) may be a rotating device. Thefurther moving endless surface (20) is typically a rotating device witha certain radius, such as a cylinder or drum or print roll, as forexample shown in the Figures. The radius of the further moving endlesssurface (20) may depend on what absorbent structure is produced, e.g.what size, and for example how many structures are produced per cycle ofthe further moving endless surface (20), e.g. print roll or drum. Forexample, the drum/print roll may have a radius of at least 40 mm, or ofat least 50 mm; it may be for example up to 300 mm, or up to 200 mm.

The further moving endless surface (20) may have any suitable width, butfor example a width corresponding to the width of the absorbentstructure to be produced; this for example be at least 40 mm, or atleast 60 mm, or for example up to 400 mm, or up to 200 mm.

Said further moving endless surface (20) may have one or more reservoirswith a certain volume for receiving said absorbent material (100)therein, and transporting it and then depositing it to said supportingsheet (200) on the moving endless surface (30) with receptacle(s) withrods (36), described above.

Such a reservoir may then correspond to an absorbent structure to beproduced. The reservoir may have a (average) longitudinal dimension, and(average) length, and a (average) transverse dimension and (average)width, said length being more than said width.

The reservoir may have raised strips (that have no void volume) andthen, when the further moving endless surface (20) moves (rotates)adjacent said moving endless surface (30) with said supporting sheet(200) on said rods (36), said raised portions may mate with (correspondto) said rods (36) (herein referred to as “mating”). Then, the absorbentmaterial (100) is deposited selectively between rods (36), e.g. in saidundulations (201).

In some embodiments, the reservoir is composed of multitude of groves,extending substantially longitudinally, or a multitude of rows ofcavities (22), extending, for receiving the absorbent material (100)therein, wherein neighboring grooves or rows are being separated fromone another by such raised strips that do not have a void volume forreceiving absorbent material (100).

Then, typically, the raised strips move adjacent (mate) said rods (36)and said crests (202) of said supporting sheet (200), and the grooves orrows of cavities (22) move adjacent (mate) with said areas of thesupporting sheet (200) between neighboring rods (36), e.g. saidundulations (201). Then, the absorbent material (100) is depositedselectively between rods (36), e.g. in said undulations (201).

The resulting absorbent structure then comprises a supporting sheet(200) with thereon a layer of absorbent material (100) withsubstantially longitudinally extending strips that comprise no absorbentmaterial (100).

The cavities (22) may have any dimensions and shape, including cubical,rectangular, cylindrical, semi-spherical, conical, or any other shape.This may be any suitable number of cavities (22), but for example atleast 20 or at least 50.

The cavities (22) may be present as identical cavities (22) or they mayvary in dimension(s) or shape. The exact pattern, dimensions etc. willdepend on the required structure to be formed, but may for example alsodepend on the particle size of the absorbent material (100), processspeed etc. In some embodiments at least 30% of the surface area of thereservoir of the further moving endless surface (20) comprises saidcavities (22), optionally at least 40%, and optionally up to 55% or upto 50%.

The distance (longitudinally) between the centre point of a cavity (saidcentre point being in the plane of the outer surface of the furthermoving endless surface (20)) and the centre point of a neighboringcavity (in a row of cavities (22)) may for example be at least 3 mm, orat least 4 mm, or at least 6 mm, or for example up to 40 mm or up to 30mm or up to 20 mm. This may apply to all such distances betweenneighboring cavities (22) longitudinally, or this may be an average overall such distances.

The distance transversely between the centre point of a cavity or groove(said centre point being in the plane of the outer surface of thefurther moving endless surface (20)) and the centre point of aneighboring cavity or groove (in a transverse line of cavities (22)) mayfor example also be as above. In some embodiments, the shortest distancetransversely between two neighboring cavities (22) of a line of cavities(22) or between neighboring groves is at least 3.0 mm, or at least 4.0mm, so that this can mate with the rods (36) of the moving endlesssurface (30).

Said rows or grooves may extend substantially parallel to, and equallyspaced from, one another and/or said lines may extend substantiallyparallel to, and equally spaced from, one another.

In some embodiments, the grooves and rows have such a shape or pattern,that the distance between neighboring groves or rows is substantiallycorresponding to a rod; and/or that the grooves or rows correspondsubstantially to the areas between neighboring rods (36). Then thegrooves or rows can mate with the areas between rods (36).

In some embodiments, the length dimension of a cavity may be (on averageover all cavities (22) and/or for each cavity; measured over the outersurface of the further moving endless surface (20)) at least 1 mm, or atleast 2 mm, or at least 4 mm, and for example at the most 20 mm or atthe most 15 mm. The width dimension may be within the same ranges asabove, or it may even be the same as the length dimensions for one ormore or each cavity.

In some embodiments, a raised portion is completely overlapping acorresponding rod.

In some embodiments, the average width dimension of each raised portionsof the reservoir(s) that mates with a rod (36) is about at least 10%more than the average width dimension of said rod.

The reservoir, cavities (22) or grooves may have any suitable deptdimension, and it may depend for example on the height of the furthermoving endless surface (20) (e.g. radius), the thickness/caliper of thedesired structure to be produced, the particle size of the material,etc. The maximum depth of a reservoir, cavities (22) or grooves and/orthe average maximum depth (average over all maximum depths of allcavities (22) and/or grooves) may for example be at least 1 mm, or atleast 1.5 mm, or for example 2 mm or more, and for example up to 20 mm,or up to 15 mm, or in some embodiment herein, up to 10 mm, or to 5 mm,or to 4 mm.

According to some embodiments herein, the cavities (22) may have a anaverage width dimension and length dimension of from 2 to 8 mm or from 3mm to 7 mm; and the cavities (22) may have a maximum depth and/oraverage maximum depth of for example from 1.5 mm to 4 mm.

A scraper or doctor blade may be used to remove excess absorbentmaterial (100). Excess material may be removed from the reservoir andrecycled back to e.g. the hopper

One possibility to hold the material in the reservoir (or its groves orcavities (22)) may be a vacuum (28) applied to the inner side of thefurther moving endless surface (20), e.g. print roll or drum, incombination with suction holes in (the bottom) of the reservoir, orgroves cavities (22) thereof, to thus apply the vacuum suction onto theabsorbent material (100). The vacuum is for example released just beforeor at the meeting point. The vacuum may be any vacuum pressure such as,just as for the moving endless surface (30) above, for example at least10 kPa, or at least 20 kPa.

The vacuum may be provided by providing one or a plurality of vacuumchambers (28) in said further moving endless surface (20) (e.g. in itsinterior), wherein said vacuum can be applied, reduced, increased, andreleased (disconnected), depending on the position thereof in theprocess/apparatus (1).

Additional air pressure and air pressure chamber(s) (29) may beused/applied to said absorbent material (100) close to or at the meetingpoint, to ensure that the material flows to the supporting sheet (200)on said moving endless surface (30).

Absorbent Material (100)

The absorbent material (100) herein is optionally a flowable material(in the dry state), such as a particulate material; it may be anymaterial in particulate form, which includes particles, flakes, fibers,spheres, agglomerated particles and other forms known in the art. Theabsorbent material (100) may be a mixture of cellulose material, orso-called airfelt, and superabsorbent polymer material.

Alternatively, or in addition, when two absorbent structures arecombined as described herein, the first absorbent structure may comprisea first absorbent material (100), and the second structure may comprisea second, different absorbent material (100), for example having adifferent capacity (CRC).

In some embodiments herein, the absorbent material (100), e.g. theparticulate absorbent material (100), comprises at least or consists of(particulate) superabsorbent polymer material, herein referred to asSAP, and also known as particulate absorbent gelling material, AGM. Theparticulate SAP herein may have a high sorption capacity, e.g. having aCRC of for example at least 20 g/g, or at 30 g/g. Upper limits may forexample be up to 150 g/g, or up to 100 g/g.

The particulate SAP may have a good permeability for liquid, forexample, having a SFC value of at least 10×10⁻⁷ cm³ s/g; or optionallyat least 30×10⁻⁷ cm³·s/g, or at least 50×10⁻⁷ cm³s/g 10×10⁻⁷ cm³s/g, orpossibly permeability SFC value of at least 100×10⁻⁷ cm³s/g, or at leasta SFC of 120×10⁻⁷ cm³ sec/g. This SFC is a measure of permeability andan indication of porosity is provided by the saline flow conductivity ofthe gel bed as described in U.S. Pat. No. 5,562,646, (Goldman et al.)issued Oct. 8, 1996 (wherein however a 0.9% NaCl solution is usedinstead of Jayco solution). Upper limits may for example be up to 350 orup to 250 (×10⁻⁷ cm³·s/g).

In some embodiments herein the polymers of said SAP are internallycross-linked and/or surface crosslinked polymers.

In some embodiments herein, the absorbent material (100) comprising orconsisting of particles of polyacrylic acids/polyacrylate polymers, forexample having a neutralization degree of from 60% to 90%, or about 75%,having for example sodium counter ions, as known in the art, e.g.surface crosslinked and/or internally crosslinked and/orpost-crosslinked polyacrylic acid/polyacrylate polymers.

In some embodiments herein, the absorbent material (100) is in the formof particles with, a mass medium particle size up to 2 mm, or between 50microns and 2 mm or to 1 mm, or optionally from 100 or 200 or 300 or 400or 500 μm, or to 1000 or to 800 or to 700 μm; as can for example bemeasured by the method set out in for example EP-A-0691133. In someembodiments of the present disclosure, the material is in the form ofparticles whereof at least 80% by weight are particles of a size between50 μm and 1200 μm and having a mass median particle size between any ofthe range combinations above. In addition, or in another embodiment ofthe present disclosure, said particles are essentially spherical. In yetanother or additional embodiment of the present disclosure the absorbentmaterial (100) has a relatively narrow range of particle sizes, e.g.with the majority (e.g. at least 80% or optionally at least 90% or evenat least 95% by weight) of particles having a particle size between 50μm and 1000 μm, optionally between 100 μm and 800 μm, and moreoptionally between 200 μm and 600 μm.

The absorbent material (100) herein may advantageously comprise lessthan 15% by weight of water, or less than 10%, or less than 8% or lessthan 5%. The water-content can be determined by the Edana test, numberERT 430.1-99 (February 1999) which involves drying the particulatematerial (100) at 105° Celsius for 3 hours and determining the moisturecontent by the weight loss of the particulate material (100) afterdrying.

The particulate SAP herein may be particles of SAP that are surfacecoated or surface treated (this not including surface-crosslinking,which may be an additional surface-treatment); such coatings and surfacetreatment steps are well known in the art, and include surface treatmentwith one or more inorganic powders, including silicates, phosphates, andcoatings of polymeric material, including elastomeric polymericmaterials, or film-forming polymeric materials.

Supporting Sheet (200)

The absorbent structure producible with the apparatus (1) and method ofthe present disclosure comprises a supporting sheet (200), to receivethe absorbent material (100). This supporting sheet (200) may be anyindividual sheet or web sheet material, in particular paper, films,wovens or nonwovens, or laminate of any of these.

In some embodiments herein, the supporting sheet (200) is a nonwoven,e.g. a nonwoven web, such as a carded nonwoven, spunbond nonwoven ormeltblown nonwoven, and including nonwoven laminates of any of these.

The fibers may be of natural or man-made origin and may be staple orcontinuous filaments or be formed in situ. Commercially available fibershave diameters ranging typically from less than about 0.001 mm to morethan about 0.2 mm and they come in several different forms: short fibers(known as staple, or chopped), continuous single fibers (filaments ormonofilaments), untwisted bundles of continuous filaments (tow), andtwisted bundles of continuous filaments (yarn). The fibers may bebicomponent fibers, for example having a sheet-core arrangement, e.g.with different polymers forming the sheet and the core. Nonwoven fabricscan be formed by many processes such as meltblowing, spunbonding,solvent spinning, electrospinning, and carding. The basis weight ofnonwoven fabrics is usually expressed in grams per square meter (gsm).

The nonwoven herein may be made of hydrophilic fibers; “Hydrophilic”describes fibers or surfaces of fibers, which are wettable by aqueousfluids (e.g. aqueous body fluids) deposited on these fibers.Hydrophilicity and wettability are typically defined in terms of contactangle and the strike through time of the fluids, for example through anonwoven fabric. This is discussed in detail in the American ChemicalSociety publication entitled “Contact angle, wettability and adhesion”,edited by Robert F. Gould (Copyright 1964). A fiber or surface of afiber is said to be wetted by a fluid (i.e. hydrophilic) when either thecontact angle between the fluid and the fiber, or its surface, is lessthan 90°, or when the fluid tends to spread spontaneously across thesurface of the fiber, both conditions are normally co-existing.Conversely, a fiber or surface of the fiber is considered to behydrophobic if the contact angle is greater than 90° and the fluid doesnot spread spontaneously across the surface of the fiber.

The supporting sheet (200) herein may be air-permeable. Films usefulherein may therefore comprise micro pores. Nonwovens herein may forexample be air permeable. The supporting sheet (200) may have forexample an air-permeability of from 40 or from 50, to 300 or to 200m³/(m²×min), as determined by EDANA method 140-1-99 (125 Pa, 38.3 cm²).The supporting sheet (200) may alternatively have a lowerair-permeability, e.g. being non-air-permeable, to for example be betterdetained on a moving surface comprising vacuum.

In preferred executions, the supporting sheet (200) is a nonwovenlaminate material, a nonwoven laminate web, for example of the SMS orSMMS type.

In order to form easily said undulations (201), the supporting sheet(200) may have a basis weight that is less than 60 gsm, or for examplethan 50 gsm, for example from 5 gsm to 40 gsm, or to 30 gsm.

Adhesive Application Units and Method Steps.

The supporting sheet (200) may comprise and adhesive prior to transferto said moving endless surface (30). Thus, the apparatus (1) herein maycomprise an adhesive application unit (51) upstream from said movingendless surface (30), and for example downstream from said supportingmaterial transfer means (210), e.g. roll. The method herein may thuscomprise such an adhesive application step. This is for example shown inFIG. 1.

This adhesive may be applied uniformly and/or continuously.

It may be applied as substantially longitudinal stripes. For example,the adhesive may be applied in substantially longitudinally extendingstripes such that areas of the supporting sheet (200) with the stripesof adhesive are between neighboring rods (36), and the areas of thesupporting sheet (200) that do not comprise said adhesive correspond tosaid rods (36), or the opposite.

In some embodiments, the apparatus (1) may comprise a unit to apply anadhesive to said supporting sheet (200) in a pattern, for example thepattern of the rods (36), or the pattern of the areas between the rods(36). This may be done by spraying, or for example by selectivelyslot-coating; the apparatus (1) may thus comprise a slot-coater, forexample with a coating pattern that corresponds to the rods (36), or theareas between the rods (36).

Any suitable adhesive can be used for this, for example so-calledhotmelt adhesives used. For example. A sprayable hot melt adhesives,such as H.B. Fuller Co. (St. Paul, Minn.) Product No. HL-1620-B, can beused.

Alternatively, or in addition, it may be beneficial to apply a furtherimmobilization adhesive to said absorbent structure produced by theapparatus (1) or method herein, e.g. to ensure the absorbent material(100) will stay substantially in the applied pattern. Thisimmobilization adhesive may then for example be applied onto saidabsorbent layer just after application of said absorbent material (100)onto said supporting sheet (200).

The apparatus (1) herein may thus have a further immobilization adhesiveapplication unit (50), e.g. downstream from said moving endless surface(30)′ meeting point. The method may have a corresponding method step.This is for example shown in FIG. 1.

This adhesive may be applied uniformly and/or homogeneously. This may bea thermoplastic adhesive material.

In accordance with certain embodiments, the thermoplastic adhesivematerial may comprise, in its entirety, a single thermoplastic polymeror a blend of thermoplastic polymers, having a softening point, asdetermined by the ASTM Method D-36-95 “Ring and Ball”, in the rangebetween 50° C. and 300° C., or alternatively the thermoplastic adhesivematerial may be a hot melt adhesive comprising at least onethermoplastic polymer in combination with other thermoplastic diluentssuch as tackifying resins, plasticizers and additives such asantioxidants. In certain embodiments, the thermoplastic polymer hastypically a molecular weight (Mw) of more than 10,000 and a glasstransition temperature (Tg) usually below room temperature or −6°C.>Tg<16° C. In certain embodiments, typical concentrations of thepolymer in a hot melt are in the range of about 20 to about 40% byweight. In certain embodiments, thermoplastic polymers may be waterinsensitive. Exemplary polymers are (styrenic) block copolymersincluding A-B-A triblock structures, A-B diblock structures and (A-B)nradial block copolymer structures wherein the A blocks arenon-elastomeric polymer blocks, typically comprising polystyrene, andthe B blocks are unsaturated conjugated diene or (partly) hydrogenatedversions of such. The B block is typically isoprene, butadiene,ethylene/butylene (hydrogenated butadiene), ethylene/propylene(hydrogenated isoprene), and mixtures thereof. Other suitablethermoplastic polymers that may be employed are metallocene polyolefins,which are ethylene polymers prepared using single-site or metallocenecatalysts. Therein, at least one comonomer can be polymerized withethylene to make a copolymer, terpolymer or higher order polymer. Alsoapplicable are amorphous polyolefins or amorphous polyalphaolefins(APAO) which are homopolymers, copolymers or terpolymers of C2 to C8alpha olefins. In exemplary embodiments, the tackifying resin hastypically a Mw below 5,000 and a Tg usually above room temperature,typical concentrations of the resin in a hot melt are in the range ofabout 30 to about 60%, and the plasticizer has a low Mw of typicallyless than 1,000 and a Tg below room temperature, with a typicalconcentration of about 0 to about 15%. In certain embodiments, thethermoplastic adhesive material is present in the form of fibers. Insome embodiments, the fibers will have an average thickness of about 1to about 50 micrometers or about 1 to about 35 micrometers and anaverage length of about 5 mm to about 50 mm or about 5 mm to about 30mm.

Further Method Steps/Apparatus (1) Units

The apparatus (1) and method herein may comprise the further step/unit,of applying a further supporting sheet (300) onto said absorbentstructure, to enclose said absorbent material (100), as know in the art.This is for example shown in FIG. 1.

The apparatus (1) and method herein may alternatively or in additioncomprise the apparatus (1) unit/method step of folding the supportingsheet (200) over the absorbent material (100) to enclose it thereby.

It may comprise a sealing unit, sealing step to seal the two supportingsheet (200) or the folded supporting sheet (200) along the peripheraledges of the absorbent structure/layer.

The absorbent structure may alternatively or in addition be combinedwith other layers, such as an acquisition layer, or topsheet and theapparatus (1) and method herein may comprise according steps/units.

The method or apparatus (1) herein may be to produce an absorbent coreor structure that comprises two or more of the above described absorbentstructures; for example two such layers, superposed on one another suchthat the absorbent material (100) of a first layer and the absorbentmaterial (100) of the other second layer are adjacent one another andsandwiched between the supporting sheet (200) of the first layer and thesupporting sheet (200) of the second layer. This is for example shown inFIG. 3.

The apparatus (1) herein may thus be a combination apparatus (1),comprising two or more, e.g. two, of the apparatuses (1) describedherein, to produce two or more, e.g. two, absorbent structures, and thencomprising a combining unit to combine the absorbent structures. Themethod may comprise according method step(s).

The strips where no absorbent material (100) of one layer is present maythen be superposed on the strips where no absorbent material (100) ispresent of the other layer, to form joined strips; alternatively, theymay be alternating, so that a strip where no absorbent material (100) ofone layer is superposed onto the absorbent material (100) of the otherlayer.

In some embodiments, when the two layers are combined, the center(referring to the width) of a (or of each of) the absorbent material(100) strips of one layer overlays and contacts the center of a (or ofthe respective) strip where no absorbent material (100) is present ofthe other layer, and optionally vice versa. Hence, one or more, or each,absorbent material (100) strip of the one layer may be placed centrallyon or in the strip without absorbent material (100) of the other layerand vice versa.

The absorbent structure produced with the method/apparatus (1) of thepresent disclosure herein may also be combined with an absorbentstructure produced by a method/apparatus (1) other than of the presentdisclosure, said combination may be done as set out above.

In some embodiments, the apparatus (1) may comprise a pressure means,such as a pressure roll (70), that can apply pressure onto the absorbentstructure, and typically on the supporting sheet thereof, and/or ontothe further material if combined with the absorbent structure asdescribed herein; or as for example shown in FIG. 3, on one of thesupporting sheets (200; 300) sandwiched on either side of the absorbentlayer or layers.

The pressure may be applied selectively onto said supporting sheet (200)or on any of the further material/layer that placed over the absorbentlayer, as described above in this section.

This pressure application may optionally be done to selectively applypressure only onto the strips of the supporting sheet (s) (200; 300) orfurther material that comprise (on the opposed surface) no absorbentmaterial (100), to avoid compaction of said absorbent material (100)itself.

Thus, the apparatus (1) may comprise a pressure means (70) that has araised pressuring pattern (71) corresponding to said rods (36), so thatthe raised pressure pattern (71) can mate with the strips of thesupporting sheet (200) that have no absorbent material (100) (on itssurface), that are or were supported by said rods (36). The method mayhave an according method step.

Absorbent Articles

The apparatus (1) and method of the present disclosure are for exampleuseful to produce absorbent structures, or absorbent cores (absorbentstructures combined with a further material, as described herein)suitable for absorbent articles.

Absorbent articles may include diapers, including fastenable diapers and(refastenable) training pants; adult incontinence undergarments (pads,diapers) feminine hygiene products (sanitary napkins, panty-liners),breast pads, care mats, bibs, wound dressing products, and the like. As

The absorbent article herein may comprise in addition to an absorbentstructure or core produced by the method/apparatus (1) herein, atopsheet and backsheet, and for example one or more side flaps or cuffs.The topsheet or cuffs or side flaps may comprise a skin care compositionor lotion or powder, known in the art, panels, including those describedin U.S. Pat. No. 5,607,760; U.S. Pat. No. 5,609,587; U.S. Pat. No.5,635,191; U.S. Pat. No. 5,643,588.

Preferred absorbent articles herein comprise a topsheet, facing thewearer in use, for example a nonwoven sheet, and/or an apertured sheet,including apertured formed films, as known in the art, and a backsheet.

The backsheet may be liquid impervious, as known in the art. Inpreferred embodiments, the liquid impervious backsheet comprises a thinplastic film such as a thermoplastic film having a thickness of about0.01 mm to about 0.05 mm. Suitable backsheet materials comprisetypically breathable material, which permit vapors to escape from thediaper while still preventing exudates from passing through thebacksheet. Suitable backsheet films include those manufactured byTredegar Industries Inc. of Terre Haute, Ind. and sold under the tradenames X15306, X10962 and X10964.

The backsheet, or any portion thereof, may be elastically extendable inone or more directions. The backsheet may be attached or joined to atopsheet, the absorbent structure/core herein, or any other element ofthe diaper by any attachment means known in the art.

Diapers herein may comprise leg cuffs and/or barrier cuffs; the articlethen typically has a pair of opposing side flaps and/or leg and/orbarrier cuffs, each of a pair being positioned adjacent one longitudinalside of the absorbent structure/core, and extending longitudinally alongsaid absorbent structure/core, and typically being mirror images of oneanother in the longitudinal axis (which may be MD axis) of the article;if leg cuffs and barrier cuffs are present, then each leg cuffs istypically positioned outwardly from a barrier cuff. The cuffs may beextending longitudinally along at least 70% of the length of thearticle. The cuff(s) may have a free longitudinal edge that can bepositioned out of the X-Y plane (longitudinal/transverse directions) ofthe article, i.e. in z-direction. The side flaps or cuffs of a pair maybe mirror images of one another in the longitudinal axis of the article.The cuffs may comprise elastic material.

The diapers herein may comprise a waistband, or for example a frontwaistband and back waist band, which may comprise elastic material.

The diaper may comprise side panels, or so-called ear panels. The diapermay comprise fastening means, to fasten the front and back, e.g. thefront and back waistband. Preferred fastening systems comprise fasteningtabs and landing zones, wherein the fastening tabs are attached orjoined to the back region of the diaper and the landing zones are partof the front region of the diaper.

The absorbent article may also include a sub-layer disposed between thetopsheet and the absorbent structure/core, capable of accepting, anddistributing and/or immobilizing bodily exudates. Suitable sublayersinclude acquisition layers, surge layers and or fecal material storagelayers, as known in the art. Suitable materials for use as the sub-layermay include large cell open foams, macro-porous compression resistantnon woven highlofts, large size particulate forms of open and closedcell foams (macro and/or microporous), highloft non-wovens, polyolefin,polystyrene, polyurethane foams or particles, structures comprising amultiplicity of vertically oriented, optionally looped, strands offibers, or optionally apertured formed films, as described above withrespect to the genital coversheet. (As used herein, the term“microporous” refers to materials that are capable of transportingfluids by capillary action, but having a mean pore size of more than 50microns. The term “macroporous” refers to materials having pores toolarge to effect capillary transport of fluid, generally having poresgreater than about 0.5 mm (mean) in diameter and more specifically,having pores greater than about 1.0 mm (mean) in diameter, but typicallyless than 10 mm or even less than 6 mm (mean).

All patents and patent applications (including any patents which issuethereon) assigned to the Procter & Gamble Company referred to herein arehereby incorporated by reference to the extent that it is consistentherewith.

This application is a divisional of U.S. application Ser. No.13/491,902, filed on Jun. 8, 2012, which claims priority to EuropeanPatent Convention Application 11169395.8, filed Jun. 10, 2011, theentireties of which are incorporated by reference herein.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

All documents cited in the Detailed Description of the presentdisclosure are, in relevant part, incorporated herein by reference; thecitation of any document is not to be construed as an admission that itis prior art with respect to the present disclosure. To the extent thatany meaning or definition of a term in this document conflicts with anymeaning or definition of the same term in a document incorporated byreference, the meaning or definition assigned to that term in thisdocument shall govern.

While particular embodiments of the present disclosure have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the present disclosure. It istherefore intended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. An apparatus for making an absorbent structurehaving an absorbent layer and therein substantially longitudinallyextending strips that are substantially free of absorbent material, saidlayer being supported on a supporting sheet, said apparatus comprising:a feeder for feeding an absorbent material to a moving endless surfaceadjacent and in close proximity thereto: a supporting sheet transportermeans, for transporting a supporting sheet to said moving endlesssurface; and said moving endless surface moving in a machine direction(MD) having an outer shell with one or more forming receptacles, havingan average width and transverse direction and dimension, and having anaverage length and longitudinal dimension, said average length beingmore than said average width; said receptacle(s) comprising a multitudeof substantially longitudinally extending rods, each rod having amaximum transverse (width) dimension of at least 0.3 mm, each of saidrods having a top portion (surface) and an opposing bottom portion(surface), said bottom portion being adjacent an inner grid, and theminimum distance transversely between neighboring rods being at least 1mm, and said rods having an average height dimension (perpendicular tothe transverse and longitudinal dimensions) of at least 1 mm; and saidmoving endless surface comprising a vacuum system applying a vacuumsuction to said receptacles or part thereof; and said feeder being afurther moving endless surface with reservoir(s), having an averagewidth and transverse direction and dimension, and having an averagelength and longitudinal dimension, said average length being more thansaid average width, and an average depth, and a void volume, being forreceiving and retaining a said absorbent material and transferring saidabsorbent material to said moving endless surface, said further movingendless surface being connected to a vacuum system to apply vacuumsuction to said reservoir(s).
 2. The apparatus of claim 1, wherein saidfurther moving endless surface's reservoir is formed by a multitude ofgrooves and/or a multitude of rows of cavities, each groove or rowextending substantially longitudinally, and said grooves and/or rowsbeing spaced from one another with raised strips, said raised stripssurface and said rods substantially coincide with one another duringabsorbent material transfer.
 3. The apparatus of claim 1, wherein saidreceptacle has a front edge zone A, and back edge zone C, with a centralzone B in between, each extending the width dimension of saidreceptacle, and said central zone B comprises said rods and front edgezone and/or back edge zone do not comprise said rods; or wherein saidreceptacle has a centre region, front region and back region, and saidreceptacle comprises said rods in said front region only, or in saidcentre region only, or in said front and centre region only.
 4. Theapparatus of claim 3, wherein said receptacle has, in said region(s) orzone(s) that not comprising said rods, a higher friction than thefriction of said rods, said central zone (B) having said rods only,having a lower friction than said front and back zones (A; C).
 5. Theapparatus of claim 1, comprising a second adhesive application unitupstream from said moving endless surface, and/or a first adhesiveapplication unit, positioned downstream of the meeting point.
 6. Theapparatus of claim 1, comprising downstream from said moving endlesssurface a unit to cover said absorbent layer with a further material,selected from unit to fold said supporting sheet over said absorbentlayer; a unit for applying a further supporting sheet; a unit forapplying a further layered material, for example an acquisitionmaterial; a unit for combining said absorbent structure with a furtherabsorbent structure.
 7. The apparatus of claim 1, comprising downstreamfrom said moving endless surface a pressure roll with a raised pressurepattern, corresponding to the pattern of said rods.